Any Wireless Local Area Network (WLAN) device that supports an IEEE 802.11 Standard (e.g., IEEE Std 802.11-1997, 802.11a, 802.11b, etc.) includes two main parts: a physical (PHY) layer signaling control device, and a medium access control (MAC) device. The function of the PHY device is to transfer bits over the air interface. Among other things, the function of the MAC device is to fairly control access to the shared air interface.
The minimal MAC protocol consists of two frames: a frame sent from a source to a destination; and an acknowledgment (ACK) from the destination that the frame was received correctly. If the MAC protocol implemented in the destination does not transmit an ACK shortly after receiving a frame, another network station may start transmitting over the air interface and the frame's source may not receive the ACK in time. If the source does not receive the ACK in time, the source attempts to retransmit the frame. In some cases, retransmissions may be frequent, which increases bandwidth consumption. In addition, if a source's retry counter reaches its limit, then the frame is discarded.
Due to delays in coding and modulation schemes used for wireless media, the amount of time that remains after receiving a message is sometimes insufficient. Accordingly, what is needed is a method for a MAC device to perform its various processes in a manner that increases the likelihood that a response (e.g., an ACK) will be sent as quickly as possible after a time period, referred to as an interframe space, expires after receiving a frame.